INCORRECT BILLING - NO CONTRACT!!!

Autopage billed me R1000 for the device itself, I asked them for my contract to see if I signed for this and they can't provide me with a contract? they said its a mistake and I will be credited but today the debit went off again 2 months in a row and still I haven't been credited?<br> To top it all off the R15 000 phone just stopped working and the insurance they say takes 2 - 6 weeks? im demanding a new phone after they gave me a faulty 1. the store did not even keep a hard copy of my contract ? there is no written agreement ? how do you do business in a financial industry with no contracts?