FALSE ADVERSTISING

I went to the MTN Cresta store on Saturday as I am due for an upgrade. Decided I will take the Huawei Nova 8i It is advertised for R289 p/m over 36 months , however the consultant then told me the best he can do is R359 p/m. When I ask for the reason, I was told it is because I am still on the old package and the ones advertised are new? In the past that was not a problem so why now? These will apparently be phased out? Why must I pay R70 p/m more? Take that R70 over 12 months and a 3 year period and I would have paid R2 520 additional for nothing? Does this then mean I need to wait for my contract to expire and hopefully then be assisted? Why advertise something if the majority of people will not get the benefit? This is poor service and in my eyes false advertising.