My suggested course of action would be to take the car to another workshop and ask them to perform two tests; a compression test and a leak down test. Ask them to provide you with the results. It won't cost much but will tell you conclusively if you have an issue with the cylinder head gasket.
If it transpires that there is an issue, I'd speak to the first workshop and see if they'd be willing to effect a warranty repair or offer some reduction to rectify the problem. If they are agreeable and do the work, explain that you will have the car compression tested again once they've completed the job.
During the replacement of a head gasket, a vital step is to ensure that the block and head mating surfaces are both perfectly clean, straight and crack free. It is critical that this part of the job be carried out with near surgical precision. The mating surfaces should be cleaned in a way which will not damage the surface in any way.
One method of checking flatness is to use a feeler gauge and a straight edge. If any evidence is seen that the cylinder head is out of true, it must be skimmed back to flat at a machine shop. A pressure test of the cylinder head also needs to be undertaken to ensure that there are no hairline cracks anywhere. If cracks are found, a machine shop may be able to weld them up or a new, refurbished or good second hand cylinder head will have to be sourced.
If the original shop either skipped any of these steps or did not re-assemble the head/block in a sufficiently clean environment or in a sufficiently careful way this may lead to the replacement gasket failing to seal. Alternatively, the new gasket may be faulty. You'd expect a decent workshop to compression test a reassembled engine but the hoses failing shortly after repair would ring alarm bells with me.
Hopefully some of this is of some use to you.
