Bad Customet service

I bought a R300 cellphone on my account on the 4th of December2017 for my 78 year old father,the phone stopped working on the 17th of the same month, as old as dad is he lost his receipt .when I took back the phone to Ackermans they said they can not help me without a receipt even if it was bought on an account.I called their head office and customer service attendant Mecay said the store must help and track the receipt.I bought R100 airtime voucher to phone them still I couldn't get help up until I told them that I will complain on hello Peter and consumer line then the lady took about 2 minutes to print my receipt that I waited for one full month, is that the kind of service that we should get from the stores? I am very angry in that my father has to wait over a month without a cell phone