VT Servicing question

[joolzh13]

I have VT'd my 2 and half year old vehicle, it has had two services with main dealer and then serviced by a specialist but they are not main dealer authorised even though many main dealers send vehicles to this garage to be repaired. I understand I am going to be penalised for not having main dealer servicing throughout the ownership but this specialist has been in business for fifty odd years. Can anyone offer advise please.