Those are built-up pedals.
Built-up pedals have a deserved reputation for fragility
KKT made better ones than others, but the design is flawed as you have found out.
Yes the vcage can be bent back (anneal it first) and the centre re-aligned and the rivetting re-done, but it will still be a bad pedal.
The worst of these are the Lyotard 136R, the axles break because they have no help from the cage when it falls apart.
Discard them and look for a similar pair (there are MANY) made with a one-piece body - KKT, MKS, SP, SR...