I called in in March to level down my MBPS speed and they told me it will start in May

I called in in March to level down my MBPS speed and they told me it will start in May. Now I called them back to check of is active and was told it will only apply in June because the person who help me did not complete my request. I told the lady is not my fault they must rectify it.her answer was it will take time to get the recording. Then she hang up. Reference number of the calls: ***1 and ***4