A BBC investigation has shown that some online retailers are still failing to comply with distance selling regulations brought in to protect consumers who shop online or through mail order.
Trading Standards has also been criticised for not doing enough to enforce this aspect of consumer law.
It is a legal obligation for sellers to give buyers a full unconditional refund, including initial delivery costs as long as the purchaser informs the seller that they wish to return the goods within seven working days.
It is because, unlike in a shop, customers are unable to examine the goods before they buy them. There are a few exceptions like unwrapped CDs and perishable goods, but otherwise the money should be credited to the buyer's account as soon as possible and within 30 days at the latest.
In June, the BBC discovered that Next had been breaking consumer law by not refunding those charges. The retailer has now changed its policy but other online shops are still failing to comply with the regulations which were brought in 10 years ago.
In September we ordered an item from online cake accessories site, Cake-Stuff.com. We cancelled the order within seven working days but the retailer failed to refund the delivery charges and still has not done so.
We purchased shoes from e-boutique, Glamorous Sole, sent them back within the cooling-off period but the delivery costs were not refunded despite requests.
The owner has now told us she only started the business in August and was not aware of this part of the law. She thanked us for pointing it out, refunded our costs and said she will always refund the charge from now on.
The clothing retailer Boden also initially failed to refund delivery charges automatically on the three occasions when we ordered and then returned goods. The retailer did though refund the charge when it was pointed out.
Boden told us that it does comply with the distance selling regulations but made some mistakes with our orders which it apologised for and stressed whenever such errors are identified they will always be rectified. It added that it offers an extended standard return period of three months.
The consumer association Which? says it is not surprised at the level of confusion we discovered.
"This year Which? has looked at more than 80 retailers and we found that over a quarter were not abiding by the laws. They are not giving shoppers their full rights," says Jenny Driscoll of Which?.
Other online retailers say it is frustrating to see firms not complying with the law.
"It cost us just over £5,000 last year in refunding delivery charges and sending out items that people had returned for another size," says Paul Neve from Ipswich, who sells riding goods from his online shop.
But as a consumer, Mr Neve has found that other firms have not refunded him the full amount. He complained to his local Trading Standards office but they told him to go to the small claims court.
"The problem with going to the small claims court to reclaim charges from £2.50 to £5 is that the cost is more than that, especially if you take into consideration the time it takes to do the paperwork and the time needed off work. It is not worth it," he says.
We asked Trading Standards officials across the UK what their policy was when faced with such complaints. We found that, depending on the office, the advice given out to consumers and the action taken varied widely.
The Trading Standards Institute said all services have to balance the demands on them with the resources that they have available.
"While services would often want to intervene in individual disputes where a business is not meeting their legal obligations, this simply is not possible in many cases," says Richard Webb, lead officer for e-commerce at the Trading Standards Institute.
"Trading Standards professionals recognise how frustrating it is for individuals who finds their complaint or problem cannot be simply resolved. However, each service will focus on the issues that matter most in their locality."
The Consumer Minister Ed Davey told us that Trading Standards have the powers to enforce the distance selling regulations and that the government is keen for them to use those powers if necessary.
"It is possible that there are Trading Standards officers out there who need more training and guidance on these regulations but I know there are many cases where Trading Standards are enforcing the regulations and Trading Standards should always be the first port of call for such complaints," he says.