Cell C good prices but Zero help

I bought the cell C 50 Gig daytime + 50 Gig night time valid for 6 months. I bought it at Welkom Mall at the Cell C office. Firstly they only take cash and secondly they refuse to give you a slip of payment. The contract is on cell C no *** installed in my wi-fi. The app on my cellphone no *** is loaded to check data left. The contract was bought on 26 October 2021. The app worked only 2 weeks although the data is working. I e-mailed for help and they promised to contact me within 48 hours. nothing happened.