Bmw East Rand taking advantage of a 74 year old pensioner

I phoned to find out if BMW EastRand Boksburg could squeeze my 74 Year old Mothers BMW *** model in for Only a Oil Change. The Lady said they can make a plan if we bring it in Straigt away (Thank you). I asked how much. The lady said Roughly R1500. But may vary on the make and model. My Son took it in and Said we only want an Oil Change. The Lady said "Oil, Filter, and Micro Filter" my son said yes. Not knowing that micro filter has nothing to do with the Oil Change. He signed the Job order and was told it will be R3000. I went through and said I wanted an oil Change only. The lady Stated that the Job Card has been Signed and tge Filter has been fitted. If I want it Removed. They will charge me to remove it. I Asked for the Service Manager who said tge Oil Filter and Micro Filter are in the same Kit. Ummmm No. I totally disagree. At the end of this. They are basically making commision On a 74 year old pensioner. Shame on You BMW Boksburg