how do we rectify the problem with our veritas R8 alarm??

We have a veritas R8 alarm, it started going off for no reason and won't stop when you put the code in. The only way to stop it was to disconnect the battery to the bell box. We've also had to disconnect the main panel or the internal siren continualy beeps. We've tried resetting it and putting in the manufacturer's code but still nothing happens. Do we need a new system??