D4 turbo issues

[Calwal]

Hi, I am really hoping someone can help.
I have v90 d4 registered in 2018.
In December 23 the engine management light came on and duly took it to the dealership for diagnostics. Was advised that the turbo had gone and needed replacement. Paid £2650 for replacement and all seemed well.
After 4000 miles, and within 3 months low oil pressure warning came up.

Volvo advised over the phone that this wasn’t their problem so I arranged for a second opinion by mobile mechanic. They advised that it was connected and the oil filter should have been changed with a full change of oil. Volvo said this was not required as part of the turbo change.

The oil level was also showing as overfilled.

Volvo reluctantly took the vehicle back, advised it was a blocked filter and needed changing.they did this free of charge.

Following this, I had a secondary oil change and filter change as they recommended after 15 miles. (Wasn’t paying Volvo the quoted 289 for this so took to independent)

Following this, the car started smoking on acceleration which got worse and worse. Took to my own garage who said it was the turbo failing again.

Again got the car towed to Volvo who confirmed on inspection the turbo had failed and they would repair under the warranty. Thought that was the last of it!

Had a call today to say it had been changed but there’s a further problem. The low pressure turbo had now failed and it would cost a further 2300 to repair that.

I really don’t know where to go with this, are the issues related? Should they have changed the oil filters and oil on turbo change (they’ve said Volvo technical say they shouldn’t) what is causing all the issues?

As I say any help would be approved at this point as after 5 months of repeated issues I need this resolving!

TIA