Voltas — Vr[censored]nit

Dear sir,
I have a Voltas vrf system installed my apartment .there is a part which has malfunctioned about 3 times during warranty and again has malfunctioned after warranty the part cost is about 40000 whenever there is a error message on ac display the compony people ask to buy a new part and also amc annually which is 25000 . For any error that comes they ask to change the same part because it is not in amc . Sir pls help us.