I have one question

my father got 1 grd floor shop rented to a restaurant 2 years ago.
but there is no tenancy agt signed, i also dont know why.

the 'tenant' run away but locked the shop and dont answer the call.
few months already

as i know if there is a tenancy agt, then we need to apply court order to evict the tenant and move his stuff

so now there is no agt, what can i do ?
can i just change the lock and threw out his stuff ?
because he try to avoiding my father call and MIA just like that