Faulty beams keep triggering my alarm

I installed my alarm about 8 months ago and the front sensor Takex beams have been problematic for the last 3 months with alarm activating for no apparent reason. This not only disturbs our sleep but send the whole family into a frenzy thinking that our security has been compromised. Are they hoping that my 12 month guarantee will run its course so they can charge me?? I insist on having my beams replaced as its defective!<br> I have called into their call centre numerous times and spoke to 3 different consultants including Chrizelda who promised to return my calls