Wrong billing,lack to zero explanation.

Since December 2025 we have been getting billed r1100,which we didn't understand but a consultant explained it is because we are on month to month basis,and we understood and upgraded on the 7th January and consultant said its upgraded,we still got billed r1100 on the 31st January 2025,we phoned on the 3rd February 2025 and again we were explained to that we on month to month,and where told to upgrade ,which we did,27th February 2025 we were billed again r1100,we phoned and again we are told we on month to month,yet we keep receiving notifications that we have less than so and so data left,yet cellc claims we on month to month basis.What kind of a **** is this?We have been with cellc for years and years ,never missed payments but now we receiving this kind of ******* service.