Beware: MTN Contract offers ....

Good morning, I took out a new contract (now have 3 with MTN) just before Christmas. The contract was for a Y5 phone advertised for R149 pm for 24 months. It was a very good offer especially for my child. This morning I received my bill just to see that it now is R171, apparently VAT has been added. I phoned MTN on the 135 number just to be told that apparently all prices exclude VAT? Where do they advertise it in the ad? I remember signing for R149 on my contract not R171 .... Can someone from MTN please rectify my contract, I think the advertising is VERY misleading.