Culio, The idea of paying the deposit on a credit card is a valid one, as long as you pay more than £100. However......do not be misled by debit cards having Visa printed on them.
There is no protection in law for using a debit card beyond that of paying by cheque. It says Visa, because Visa came to an agreement with many of the banks to carry out the electronic funds transfer. However, this is just a direct funds transfer between your bank and the payee, and does not go through a credit card account.
The banks pay a standard rate to Visa be part of the clearing system, and there are no transaction fees. This is why many sites charge an additional cost for using credit, but not debit cards.
Also, be aware that you do need the receipt showing deposit....and ideally all the details on one receipt. Finally, you need the receipt to show what you are receiving for the payment (ie 45 hours training), so that if you do have to make a claim, you can validate it.
You should then be covered for whatever proportion of the training you don't receive if the company goes under.
....On another note, it occurs to me that training organisations should start arranging loans, with interest and cover. That way, they get their money up front, you get to pay in installments, the current interest rates probably mean its worth it, and one tick box covers you if the company goes under (or if you lose your job!) How about it?
Hope that is of help.