Assist me with this kind of *****

Hello peter am Nompathontle Mbele am writing this regarding of what mtn and Mondo did to me as client.. on the 31 of January 2024 I've received a call from Mbalentle Mpulo with this number *** telling me about the data package they have which is R149 of 15mb with contract. So I took the package after a week i received my package, she called me checking whether my bundles are working, I told her it's working then questioning her is this R149 package of data bundles you gave me she said let me check to be sure, then she did check from system after that she told me she made a mistake she gave me the package of R159 of 15 data bundles instead of R149, I told her we signed and agreed with the contract package of R149 , her answer she gave me am sorry client I've made a mistake I will fix now, Then I will do cancelation for this one and give you the right package you wanted and signed of. You know what she did, she did the second contract in the name of she's fixing the mistake she did. On the 1st of febr 2024 I went to mtn shop to check is everything went well according what Mbalentle Mpulo said, the guy was assisting me he said under my name I have to contracts,we had fight the he insisted that in order to fix this I must call Mtn then mtn gave me the number I must have clearance of what is happening which is ***, the lady who did this is one of their Urgents which is Mbalentle Mpulo. Top of this mess she did there's something called Prorata didn't even mentioned to me , i asked her many times when about this, on the month end the will be no extra payments for this package, tI will pay R149 only ?she keep on saying yes there will be no extra money you will pay. What is painful and weird when mtn sent me a bill, just found the amount of R578 I must pay for each of these contracts. I've tried to disputes this but mtn and mondo were not willing to help me sometimes they just saying there will get back to me for feedback since February till now April. Hello peter kindly assist me with this matter.