Upgrade to Compact Plus advertising just another Marketing Ploy !!****

So DSTV sent me an email to say that I could upgrade from Compact to Compact Plus ,for just an extra R75. The naive me went on online to to do this upgrade , guess what DSTV now want me to pay R124 (Which equated to R509 - the actual premium for the Dstv compact plus package) . What happened to paying only R75 as per your adverti*****t ??