A garage diagnosed a bad head gasket on my car 2 days after I bought it. (warranty wise paid) later found out HG does not appear to have been replaced.

Car is a 2006 mk2 ford focus sport 1.8 tdci

few months back someone replaced a rad hose, didn't put it back on correctly and during driving I noticed it overheat, had not been driving too long. about 6 months later I began having problems.
I notice drop in water level, no leaks found. had a chemical test done, changed colour indication failed HG. (I'm wondering if it picked up on last time HG went shortly after buying car, if it actually did)

Since then the radiator leaked so I replaced it, 2 rubber rad hoses leaked, and a metal cooling pipe burst. top rad hose feel's rather hard imo. when removing rad cap pressure seems high imo.

Other than that, I see no oil/water mix, no power loss, no smoke (even in cold weather), and it has been over 15 months since diagnosis.

any thoughts on this ??

thanks all

(I'd get Hg replaced if it needs it but experiencing other problems too and not sure it'd be worth it , )