How to fix my CO2 diffuser

[Aqualover]

I just bought a co2 kit for the ista 0.5 tank with the 2 in 1 bubble counter and diffuser, so after three 3 days with the diffuser working perfectly then suddenly my air tube had a hole in it which resulted with the co2 freezing and the PSI lowering bit I stopped it. But the lowering of the psi kept slowly lowering until it stopped also my regulator could not control or adjust my psi because it was an ista 0.5 tank so after the incident the bubbles would still apear from the 2 in 1 diffuser but when I woke up to day, I didn't see any bubbles bUT the tank is still 2/3 full

 What do you think I shold do? 

I just want to fix my diffuser

 

[jayc]

Maybe return the unit for a replacement.

It would be difficult repairing something like this.