Why cant LUL open ticket offices as advertised?

London Underground continually fails to open ticket offices because of staff shortages, as the board in the picture testifies.
How can it be thus, there were 33 agency workers sacked by LUL earlier this year? These workers were ticket office clerks, staff who would have been able to open ticket offices that LUL claim they have not enough staff for.
The Mayor, in his election manifesto, promised to keep ALL ticket offices open. Has the Mayor reneged on yet another election promise or will he now take LUL to task and ascertain why ticket offices routinely fail to open because of staff shortages?
There are 33 RMT member’s more than willing to step up to the task to ensure in future LUL are able to open ticket offices as advertised, after all it is a world class customer service LUL seek to provide isn’t it?
The justice for the 33 campaign demands that these agency workers, wrongly sacked by LUL be taken back on in full time employment. Having ticket offices unable to open because of a lack of trained staff is a poor excuse when LUL could solve the issue at a stroke by re-employing the 33