I can't make sense of that. '999 calls' is a noun phrase: phone calls to the emergency number. They peak (verb): that is, they are reaching a peak. Or they spike (verb): that is, they shoot up in a spike. Such a spike is of course probably a peak also. But I can't see how there can be a peak of a spike: with '999 calls spike' a noun phrase (a spike in 999 calls) peaking (its verb). I don't understand how 'spike' and 'peak' work together.
I wonder if the headline spread across onto the right hand page, and it should read "999 calls spike [...] peak but relief [...]". I might possibly come up with some explanation for "spike peak", but I cannot think of any explanation for "but relief", if nothing else follows.