Piaggio Scooters Vespa - Technical issue not resolved

My wife has a VESPA with the below details.
Chassis no. : MET****BASA******
Registration number: TN ** BA ****
Registered name : Dr.T.Sukanya
Dealer : Purchased from Rajeshwari Motors
Registered mobile number : **********/**********
This vehicle is having a breakdown complaint from the initial stage of purchase and the same has been reported to the dealers, customer care and the solution received is not satisfactory. I have attached the emails written to the customer care dated back to **** for your reference. Once we escalate the issue the problem is resolved temporarily. And every time the service staff convinces us that the problem is resolved completely and we agree. And the problem occurs again, i am not sure if its a manufacturing defect or unskilled services staff at the outlets. I have taken my breakdown vehicles to different service centres at Namakkal, Salem, Erode and Tiruchengode to find the problem and rectify on my own expenses but nothing has helped us in solving the issue. I am really disappointed as our time and money is wasted every time without a proper solution.

Currently my vehicle is at Tiruchengode service centre (Aruna Wheels, No ***/*, Old D No ***/**A, New No ** Ward G Block, Katcheri Street, Tiruchengode - Paramathi - Velur Rd, Tiruchengode, Tamil Nadu ******) where it was repaired * months ago for breakdown issues and now it's back to the service centre for the same issue. And now the service staff says that they will replace the spare at our cost as spares are not covered in warranty and can't guarantee if the spare will last for a longer time as they cant find the actual problem. So I need to shell out Rs.**** every two months just to replace the spare which lasts only for a month due to some other technical issues in the vehicle.

Moreover, everytime the vehicle is in the workshop for breakdown check it is there for weeks to get it repaired as they try to find the problem which is yet to be resolved.