It can seem impossible to get a fair result when you are battling a large, faceless organisation alone. But never fear! The AOL Money Fixer is here to help.
This week, she offers advice to a reader who sent a £300 deposit to an online car dealership that is now ignoring his calls and emails.
I recently paid a deposit on a secondhand Volkswagen Golf advertised by a small internet dealership.
I wanted to pay the amount - £300 - by credit card, but the dealer told me by email that he was unable to accept credit card payments. I therefore actioned a bank transfer to his account.
After that, however, I never heard anything more back from him. I have tried to get in touch a number of times, but the phone number I have - a mobile number - does not seem to work.
There is no address on the website and my numerous emails, sent over the last two weeks, have also had no response.
I have contacted my bank, but it says that it cannot recall the payment and I do not know what to do next. Is there any way I can get my money back?
D Cutler, London
The internet can be a great place to find a cheap new, or secondhand, car.
Under Distance Selling Regulations introduced in 2000, internet buyers also have an automatic seven-day cooling off period from taking delivery of a car - even if, like you, only the deposit was paid online.
However, it is always sensible to go to view the vehicle in person before handing over any cash.
There are fraudulent sellers out there, and some people even unluckier than you have lost the entire sale price after sending it via a bank transfer or through PayPal - only for the seller to "disappear".
The Auto Trader website does not support any methods of online payment for this reason. Its tips for avoiding situations of this kind include treating sellers who ask you to wire large amounts of money or cannot give you a landline phone number with caution.
It is a shame - although hardly surprising - that you were unable to pay by credit card as under section 75 of the Consumer Credit Act, credit card companies are jointly and severally liable for payments of between £100 and £30,000.
Consequently, had you paid by card, you could have contacted your card provider for a refund of the £300 that you seem to have lost. As you paid by bank transfer, however, this option is not open to you.
The best thing to do is therefore to contact government-backed Action Fraud on 0300 123 2040 or the Citizens Advice consumer line on 0845 404 0506.
You may well find that one of them is already aware of the illegal activities of this online dealer. For more details on how to protect yourself in the future when buying a car online, it is also worth visiting the Buyer Beware page of the DirectGov website.
Whatever your financial problem, write to firstname.lastname@example.org and The AOL Money Fixer will get on the case.