take1.php

<section class="section // section--base // section--fixed">
	<div class="container">

		<?php
		//Array (Feature Title, Feature Description, Icon Class);

		$adverts = array (
			array('No Call Out Charge','Free quotation for all jobs','no-callout'),
			array('Qualified Plumbers','Qualified Gas Safe Engineers','tick'),
			array('Free Quotations','No obligation free quotations','contract'),
			array('Great Service','Knowledgeable, experienced staff','thumb'),
			array('5 Star Reviews','We are trustworthy and reliable','star'),
			array('No Call Center','Speak with our experienced staff','no-call-center'),

		);
		
		$selected_adverts = array_rand($adverts, 2);
		
		foreach($selected_adverts as $selected_advert)
		{
			echo '<div class="feature-half">';
			echo '<svg class="icon icon-feature" aria-labelledby="title-icon-'.$adverts[$selected_advert][2].'" aria-describedby="desc-icon-'.$adverts[$selected_advert][2].'"><use xlink:href="/assets/img/icons.svg#icon-'.$adverts[$selected_advert][2].'"></use></svg>';
			echo '<h2 class="feature-half__title">'.$adverts[$selected_advert][0].'</h2>';
			echo '<p class="feature-half__text">'.$adverts[$selected_advert][1].'&hellip;</p>';
			echo '</div>';
		}
		?>

		<div class="feature-half__cta">
			<?php include($_SERVER['DOCUMENT_ROOT'].'/includes/module.tel.php'); ?>
		</div>
	</div>
</section>

take2.php

<section class="section // section--base // section--fixed">
	<div class="container">

		<?php
		//Array (Feature Title, Feature Description, Icon Class);

		$adverts = array (
			array('title' => 'No Call Out Charge', 'text' => 'Free quotation for all jobs', 'icon' => 'no-callout'),
			array('title' => 'Qualified Plumbers', 'text' => 'Qualified Gas Safe Engineers', 'icon' => 'tick'),
			array('title' => 'Free Quotations', 'text' => 'No obligation free quotations', 'icon' => 'contract'),
			array('title' => 'Great Service', 'text' => 'Knowledgeable, experienced staff', 'icon' => 'thumb'),
			array('title' => '5 Star Reviews', 'text' => 'We are trustworthy and reliable', 'icon' => 'star'),
			array('title' => 'No Call Center', 'text' => 'Speak with our experienced staff', 'icon' => 'no-call-center'),

		);
		
		$selected_adverts = array_rand($adverts, 2);
		
		foreach($selected_adverts as $selected_advert)
		{
			echo '<div class="feature-half">';
			echo '<svg class="icon icon-feature" aria-labelledby="title-icon-'.$adverts[$selected_advert]['icon'].'" aria-describedby="desc-icon-'.$adverts[$selected_advert]['icon'].'"><use xlink:href="/assets/img/icons.svg#icon-'.$selected_advert['icon'].'"></use></svg>';
			echo '<h2 class="feature-half__title">'.$adverts[$selected_advert]['title'].'</h2>';
			echo '<p class="feature-half__text">'.$adverts[$selected_advert]['text'].'&hellip;</p>';
			echo '</div>';
		}
		?>

		<div class="feature-half__cta">
			<?php include($_SERVER['DOCUMENT_ROOT'].'/includes/module.tel.php'); ?>
		</div>
	</div>
</section>

Either will work - the 2nd example is more readable if you can change the original array to be associative.