Rain is a ****

I bought 5g device in May ,within seven days I tried to cancel without luck since ,then in July I requested a downgrade to 4g,but they said I must pay the outstanding amount, then they will automatically cancel the 5g and send me the 4g Sim card,,I did pay the balance ,and apply for 4g which is R250,in august they said I must pay R550 if I'm not mistaken,,I paid it then September, when I check,before the debit order date,to my surprise i found out that they say I must pay R750,,I called them and the lady I was talking to said they need proof that I canceled the 5g in July,, after few days,they closed the 4g Sim,, so now they are busy taking my money and m surprised that it's not a debit order but a purchase , that means they are using my card number for purchase, they called me on sunday and promised to cancel everything and refund me,,but they took money again this morning