Yes. He is pyramiding. Pyramiding is caused by growth in conditions that are too dry.
Your substrate looks much too dry, and that Pets At Home stuff with the limestone bits in it is very dangerous. Encouraging a tortoise to eat its substrate to satisfy calcium cravings is a bad idea.
Which is due to the wrong humidity I have just brought some moss and a hydrometer so that I can monitor and increase humidity for him do you know where is the best place to put the monitor? And what substrate I should be using as the pro rep one isn't good