Vauxhall Crossland X engine running rough and high oil consumption

We had a wet belt replacement and full service in October. 4,000 miles done since then yet we have needed to add another 3-4 litres of oil. A litre was added with a short drive around the block and when this was checked on return it wasn't even touching the dipstick

In the last 3 months we have had to replace 3 ignition coils and the crankshaft sensor. One of the coils has since gone again and on inspection the plug attached to the coil is absolutely fried. Dealership has advised we need to pay for two different diagnostic tests for each issue meaning this would cost just under £400 on its own.

There is also a communication lock on the car meaning when scanned no other garage including recovery can communicate with the car!