Poor record management of payment

One week after my issue with payment of account I received the following sms: Cell C customer, please pay your account urgently to avoid negative credit listing. Please call 084140 to make a payment arrangement. Cell C. I have checked on my banking app that the amount of R1120 was paid on 09 Oct 17. How many time must I phone 140 and email proof of payment to ********** and ********** before this harassment stops. The one number ********** 602 is my parents line and the are old and sick, what will happen if there is emergency and they cannot call someone to help? Will Cell C take accountability? They stay in Hoffmeyr in the Eastern Cape far from Dr's and medical care. Please phone me on ********** 165 to resolved this matter finally.