Missing data bundles

Early in May my 10gig bundle was used up at night. I bought a 25gig top up bundle and this was also used up at night. My router and SIM card are in my office (I work from home) so only my wife and I have access to these. After the first theft the router was switched off at night to prevent unauthorised usage from taking place. Despite this the 25gig was also ******, again late at night. A complaint was lodged with Telkom. Never heard anything. At end July another 4gig vanished. Another complaint was lodged. They called today, claim that it has nothing to do with Telkom and that I am responsible for the safety of the SIM. Pointed out the above and was politely told that Telkom cannot accept what the customer claims i.e. customers are *****. The person that I spoke to confirmed that they have had many complaints relating to missing data bundles. They will not acknowledge this and are avoiding the issue. Have had billing issues with them as well. AVOID THEM LIKE THE PLAGUE.