App store

Hello, I have just had £44 taken out of my bank from iTunes, I've looked through my settings and It says I've subscribed to an app called Mlock-secure but I haven't, I haven't entered any of my bank details to them or given them any kind of consent to allow them to take money out of my bank so I would like know if you could help me figure out how I can get my money back because I haven't purchased anything from iTunes or subscribed to anything especially anything costing £44. Thanks. My phone is telli me I have downloaded the app but I haven't and the date of the money being taken out of my back i was at work all day and was not even on my phone so I don't know why this is happeded.

This is the app