S60 D4 2.0D 6speed manual(2015) Turbo problem

[Londonr]

Bought this 2015 S60 with 167K on clock. Today a low oil warning came. I was thinking of changing Oil and Filter anyway, so took it to the garage for oil n filter change. When the lower shield was taken off, there were drops of oil coming down slowly. When mechanic did it’s enquiry with torch, he said it’s turbo is gone hence it’s losing oil. Oil is topped up now and warning gone. I checked online and there are few available. I was wondering if it has to be a 2.0 turbo required for my car or others like 1.6 or 2.4 can still be fitted on this d4 engine. Is it a twin turbo engine or single turbo?
Any help in this regards will be appreciated. Thanks

[Londonr]

Bought this car 2 weeks ago with 167k on clock. A week later car gave an engine warning light. Diagnosis told it’s an EGR problem. Rang Volvo dealership to book a repair. Glad to hear that Volvo changing it free of cost. Car left with dealership and was returned next day with problem solved. Not the best of customer service provided. On receiving car back, no one was present at reception desk, with few staff flying past with no one paying attention. Finally the guy who booked my car in came with keys and handed over to me with the statement “your car’s parked outside in street” and walking away. On my enquiring what was replaced in my car( I was expecting a few words feedback about problem and parts used to fix the problem) he said EGR replaced. I requested a receipt about work done or parts used, answer was negative & he walked away.
I wrote an email to the dealership to provide a proof of documents like receipts or anything so that I can keep a track of work done on my car. It’s been a week and no reply yet.
My question is, did they actually changed EGR or just cleaned a reset the system. Denying to provide receipts is making me a bit suspicious
Please help me and share your own experience if you got a recent one.
Regards