So your problem is how to get to the innest part of the respective data items, that can be achieved by exploding the inner items using different delimiters, see example:
<?php
$value = "Name=Steve:Phone=+0154155423,Name=Jack:Phone=+013935175713,Name=Sarah:Phone=012376479150";
$values = explode(',',$value);
print_r($values);
echo '<br>';
foreach($values as $item){
$pairs = explode(':',$item);
print_r($pairs);
echo '<br>';
$namePair = explode('=',$pairs[0]);
$nameValue = $namePair[1];
print_r($nameValue);
echo '<br>';
$phonePair = explode('=',$pairs[1]);
$phoneValue = $phonePair[1];
print_r($phoneValue);
echo '<br>';
}
?>
and the outcome:
Array ( [0] => Name=Steve:Phone=+0154155423 [1] => Name=Jack:Phone=+013935175713 [2] => Name=Sarah:Phone=012376479150 )
Array ( [0] => Name=Steve [1] => Phone=+0154155423 )
Steve
+0154155423
Array ( [0] => Name=Jack [1] => Phone=+013935175713 )
Jack
+013935175713
Array ( [0] => Name=Sarah [1] => Phone=012376479150 )
Sarah
012376479150
Study the code to figure how to pick out the respective name and phone values for insertion to mysql.