Distorted upvc windows, no lintels

[oaplumber]

When my wooden windows were replaced I was told the new upvc windows were load bearing and contained steel. Therefore no lintels were needed. The soldier courses above 3 windows have now slipped and the weight is distorting the windows and cills. I am having to get lintels fitted, but am concerned about the windows distortion. Will the upvc return to it's original shape,or will it stay bowed ?
The fitting was done about a year ago.

[welsh brickie]

the windows need repacking,so long as the corner welds are not cracked they will be ok.