MTN blocks second sim on dual sim phones

I upgraded to a Huawei P30 Lite dual sim version. Just to find out that MTN blocks/disables the second sim, after falsely advertising that it is a dual sim. The job of the consultant is to inform the customer before purchase that the advert was actually a lie and that they instead only enable one sim! I specifically upgraded for the feature since i want to put a data sim in second slot. Now i still need to charge and carry around an additional phone/device to insert my second sim card? Does this make sense? What was the point of purchasing a dual sim phone if I cannot use it?!

I would like MTN to sort out this matter because they are actually being ****** and *****! I also want the second sim unblocked.