Just called the boss (Steve) at Kwik Fit on Woodchurch Road to check.
Yes the colder or free promotion is on.
Standard price for a re-gas is £49
If you have a service at the same time then the re-gas drops to £25
Hope this helps, if you need to know anything else or book it in then their number is 0151 608 4821 (no I don't work there