err, did you leave on good terms ??
if so, could they possibly be the answer ? as they may welll need some IT now, and you are in a position to ask for a proper rate for the job too, and you would be most definiteley ‘hit the ground running’ :o)
OR, if you left on bad terms, and you are failing to get past interview stage, it MAY be they have poisoned the well as it were - not saying they have, as it is not something Co’s do, as it bites both ways
one other, have an HONEST discussion about your interview techique
do you turn up on time ? are you dressed well ? tidy / clean / sweet smelling - the whole enchilada :oP
they say interviews are won or lost in those initial first few seconds, so take any criticism from friends on the chin, and adapt to get the job
also training, MS have theor online virtual academy, lots of FREE courses, with online as you progress tests, they may not be street cred certs, but MS like them, and you can PROVE them by logging into the academy too
maybe start to look into Linux too, as that is ALWAYS going to be a worthwhile ticket to have
not free, but not too expensive, and all is provided to help you get into it from the get go
https://linuxacademy.com/
you have a degree, it doesn’t really help, but A+ / Network + show you have some ability at the beginner side of things, so not really worth looking into more as you already have experience, so maybe an MS cert to MCSA is the way to BEGIN, but IT is all about training, and staying current, not all want or see the need to re-certify, so there are a lot of MCSE NT4 / 2K3 out there as they have maintained presence within the system, and so are still current, but there is NO point in you bothering with old certs, so for what its worth, my 2c are to the links above, get a job you like and want to progess in, and then commence / complete the cert path that is best suited to the path chosen