Poorest service ever

After signing up for a package of R589... Im forced to pay R654 just 3weeks later... I signed up on the 11may 2020...on the 2nd of june i get an invoice saying the amount with be increased to R608 and just a day later R654... This is extremely and the poorest service I've ever received from any network provider... How do you not notify a customer before they sign up about these things? Doesnt an increase accur after a year of having the contract? I signed up for R589... Where does the 2 different invoices and a total difference of R70 come in? And then you just get told everyone was notified beginning of April... I was not a customer that time... And was not advised of fhis when i signed up in Middle May