repair days becomes repair months..??

I bought a Hoover vacuum cleaner but lost the purchase slip that was stuck onto the box. after 3 months, the machine failed and would not come on. The store manager said I can bring it in for repairs if I can bring my bank statement which reflects the EFT transaction which I did. The lady then told me I have to wait for them to find the sale on their system before it can be send away. 3 Weeks later, no call, and when I phoned they did not even have the transaction - waiting for a guy at head office with a computer? Surely Computers are faster than this? Needless to say I am not holding my breath and should have done the repair myself because it is likely to take months and not days at this rate!