CO2 problem

[Ruth]

On one of my calcium reactors (grotech) my last bottle of CO2 (first time filling a new bottle) only lasted me like 2 months. I have my bubble count at about 80 per minute. I thought this was weird because my other bottle on my other CR (Precision Marine) is still going after 8 months. OK so I took it back to the fill er up place and told them about the problem. They said they had been having a problem with their filler er upper and only charged me half price. That was last week. Now what I didn't do is to read the regulator guage to see what it read. I use 2 bubble counters - the one attached to the regulator and the one that is part of the reactor and both were bubbling at about the same rate.
Anyway this morning I glance over and no bubbles - OK go and turn up a bit higher - still no bubbles. Look and no CO2 in tank. What is going on. I know I either have a leak somewhere - no hissing noise at all - or they are not filling up my bottle? Any suggestions?