Mate I would drop the oil, see how much is Actually in there then replace, just because a garage has ( supposedly) changed the oil it doesn't Acctually mean jack #hit,
My mate had a Hayabusa, (motorcycle) and had it serviced at a reputable shop, he bought it to me when it stopped running, after doing a fault code test it came up cam sensor, I removed it and noticed that the cam wasn't moving on start, when I removed the head, I found that the cam chain had snapped and wrecked all 3 guides and bent 8 of 16 valves, the head was on the bench when he came round to look and he said whose head is that I said yours mate he said cant be as I had the shop put split fire plugs in on the last service well low and behold they had charged him for them and left the old ones in, so they probably changed nothing, lesson learnt