Duotrav Eye Drops - What is going on????

Good day, my Dad is using Duotrav Eye drops and it is the 5th time that he has reported that the drops that is supposed to last a month, lasts 2 days. Please can someone from Alcon assist here, trying to call the call center may be helpful if someone actually answers the call. This is ***** and needs to be urgently investigated!!! Furthermore your customer service is pathetic so there is no one to report this to. I am certain this is not the only complaint regarding Duotrav, a bottle costs about R350 and each month we have had to buy about 4 bottles instead of 1 bottle. HELP!!!!!