Last night at 2126 I received 9 consecutive text messages from an unknown number to me "69030." All received in less than 60 seconds!

Most days I check my remaining minutes via an app i have downloaded as i only have 100 minutes per month. I've just checked now, and in a way i am glad i have. ::)
This number which text me last night has showed up on my account at £1.50 per message!
What do you suggest i do? Anyone head of this kind of scam before? Here are a couple of other peoples comments i have found when i google the number http://www.smswatchdog.com/text-message-from/69030
http://whotextsme.com/text-message-from/69030
First thing i have already done is cancel my direct debit!
